Using Ovaprim to Induce Spawning in Cultured Fish

Using Ovaprim is quick and easy method to advance and synchronize spawning times in mature cultured fish. The results are predicable and reliable without affecting fecundity, fertility and survival. In males, milt production is increased and in females, maturation of ova is complete without adverse affects. Ovaprim can be used in a variety of cultured fish and in many applications such as to synchronize spawning times, compress the spawning season, induce maturation in hard to breed fish and increase milt production. Ovaprim has emerged worldwide as a key tool in broodstock management.

Product Description

Ovaprim contains a potent analogue of a naturally occurring brain peptide. This peptide initiates maturation in all species of fish through the fishes’ own internal mechanisms. Ovaprim comes as liquid that is injected into the fish during the spawning season. The active ingredients in Ovaprim induce the fish into maturing within a week to 10 days. The peptide vehicle is 100% biodegradable, is inert and will not harm the fish or humans.

Method of action

The active ingredients of Ovaprim are the analogue of salmon GnRH (sGnRHa) and a dopamine inhibitor. The native GnRH peptide is released from brain cells of the hypothalamus that then bind to receptors on pituitary cells. The sGnRHa in Ovaprim acts in this fashion except that it:

• travels to the pituitary from the injection site through the blood,
• is present in greater than physiological amounts and
• binds to the pituitary receptors with a greater affinity than native peptide and hence is more potent.

These three factors, external source, greater availability and greater potency, serve to induce a spontaneous liberation of maturational hormones from the pituitary. These pituitary hormones elicit gonad maturation together with the constituent and complementary hormone production from the gonads. The result is the earlier, complete production of viable eggs and milt.

Applications

Ovaprim can be used in any population of fish during or shortly before the spawning season. Ovaprim can advance maturation dates by up to 4 weeks in populations with a uniform and short spawning period. In other cases, Ovaprim can move spawning dates by 1-2 weeks. When used within a spawning population, Ovaprim will compress the spawning season to within 1-2 weeks post-injection. Ovaprim can also be used in fish that have been photoperiod controlled. There is no substitute for well-described broodstock performance and the best results for using Ovaprim are in stocks with a recorded spawning history.

Typical uses

There are four main uses of Ovaprim:

1. To synchronize spawning dates in a population. Synchronized spawning dates give producers a greater flexibility in marketing ova and offspring. It also has many beneficial downstream effects that are realized when spawning is confined to a predictable and defined period.
2. To compress the spawning season. Often fish in a population will spawn over a protracted period. Ovaprim can compress and shorten the spawning season that permits optimization of time and resources.
3. To induce maturation in reluctant fish. Sometimes breeders will not cooperate while mates are in season. Ovaprim can help to induce maturation in a natural way without effecting gamete viability.
4. To increase milt production. Chronic problems of milt shortages are commonplace in aquaculture. This may disrupt detailed breeding programs. Ovaprim serves to increase milt production in males.

Species list

Ovaprim can be used in all species of fish. The forms of GnRH that naturally occur in the brains of fishes differ throughout the more than 25,000 fish species. However, the salmon form of GnRH is present in most of these fish and thus the sGnRHa in Ovaprim is the peptide of choice. Among the other types of GnRH found in the other fishes, there is such a conservation of form and function that Ovaprim works successfully. Ovaprim has been used successfully in all major types of fish including:

• ornamentals
• salmonids
• cyprinids (goldfish, carp)
• catfish
• perch (sea bream, tilapia).

Ovaprim contains a dopamine inhibitor that is essential for inducing reproduction in cyprinids. For specific application of Ovaprim to your fish, consult Syndel Labs.

Critical Requirements

It is primarily important that the protocols of Ovaprim be used for successful results. Paramount is defining the intended purpose: synchronize maturation, compressed spawning, induce maturation and increase milt production. In each of these applications the timing of Ovaprim use differs. Generally, Ovaprim is most effective when used within the spawning season.

Packaging and Presentation

Ovaprim comes as a liquid in two sizes (10 and 100ml) of re-sealable bottles. The liquid is ready to use and comes in a standard dose that is delivered to the fish through a standard syringe and needle. Correct injected volume is achieved by multiplying the weight of the fish by 0.5ml/kg. This delivers enough active ingredients to induce the desired effect. For milt production in most male fish, the dose is reduced by half. To apply, simply insert the needle in the bottle, withdraw a sufficient volume and inject Ovaprim into the abdominal cavity. Ovaprim is stable at room temperature and should be stored out of direct light. When kept this way, Ovaprim will last for up to a year. Again, it is most important to follow established protocols for using Ovaprim.